Mold and process for forming articles from pulp or other plastic material



Feb. 24,- 1925. 1,527,787

S. CCOPER MOLD AND PROCESS FOR FORMING ARTICLES FROM PULP OR OTHER PLASTIC MATERIAL Original Filed July 30, 1921 MW M Patented Feb. 24, 1925. I

UNITED STATES SIMON COOPER, OF BROOKLYN, NEW YORK.

MOLD AND rnoonss FOR roma ne ARTICLES FROM PULP on ornnn PLASTIC MATERIAL.

Continuation of application Serial No, 488,679, filed July 30, 1921. Serial No. 550,261.

To all whom it may concern:

Be it known that I, SIMON COOPER, a citizen of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Molds and Processes for Forming Articles from Pulp or Other Plastic Material, of which the following is a specification.

This is a continuation plication Serial No., 488,679 filed July 30, 1921, and it is intended to secure in thisapplication the benefit ofthe filing date of my of material, as it rises in the mold, to become depleted before it reaches the top of the mold, resulting in\a weaker deposit of pulp at the top than elsewhere. This is a disadvantage in the case of bottles and the like, which aremolded in inverted position be cause it results in the bottom of the bottle (the top part in the mold) being the weakest part of the article. a

The primary object of my invention is to overcome this fault, and this I have done by introducing into the mold at the proper time a supplementary supply of material to augment or reinforce the deposit at the top of the mold. r

' In theaccompanying drawing I have illustrated a practical embodiment of means for" carrying out this invention, wherein Figure 1 is a view in side elevation of the complete apparatus; and Figure 2 is a vertical sectional view taken through the suction chamber and pulp reservoir.

Considering the illustration in detail: 5 designates a suitable pump or suction-producing device, connected by piping 6, with the-vacuum or suction chamber 7, a vacuum tank '8, of appropriate size being interposed in this line of piping to overcome pulsations of my former ap- This applicationfiled April 7,1922.

of the pump and provide a certain reserve of suction force.

Within the suction chamber is mounted the mold, having porous walls 9 of gauze or the like conformed to the shape of the article tobe produced, a milk bottle in the case illustrated, and braced by suitable ribbing 10. The base 11 of the mold is also porous and the mold is preferably made in sectionsto enable ready removal of the molded product therefrom. This mold is supported in an inverted position on a 1101- low column or tube 12, whose lower end dips into a pulp reservoir 13.

The usual mode of operation is, by means of a finely regulatable valve 14 (valve 20 being closed and valves 24 and 25 open), to .admit first a reduced degree of suctionto the suction chamber so as to fill the mold gradually, rather than suddenly as would happen if valve 20 were opened suddenly. As the column of pulp rises in the mold, the liquid and lighter particles pass through the interstices or pores, leaving a layer of pulp deposited on the walls of the mold, this deposit progressing as the pulp rises. This gradual movement results in a well mattedor felted facing deposit and is followed by an interval of full suction to increase the thickness of deposit.

- There is a tendency for the mixture to become weakened or depleted in strength before itreaches the top of the mold. To overcome or offset this weakenin effect, I admit a supplementary supply of material .to that portion of the mold where reinforcement is necessary or desirable. In the drawing this is done by means of a conduit 15, dipping into the pulp reservoir and extending up into the upper portion of the mold, where it terminates in a funnelshaped spout 16, disposed quite close to the top of the mold. This conduit is shown controlled by a valve 17, and said valve is indicated as of the two-way type for also controlling a connection 18, to atmosphere.

The usual method of utilizing the additional or supplementary ulp suppl thus afforded is to open valve 1 to the pu ply just as the rising column of mixture reaches the top and the mold chamber becomes filled. This causes a supplementary deposit of fresh undiluted pulp to be superimposed upon the deposit'made on the top of phere. This releases the suction effect, gradually producing an equilibrium of pressure at the top and base of the pulp column, as the incoming air slowly passes through the deposited pulp, thereby allowing the excess pulp to drain slowly back into the reservoir.

The valve 17 is then closed against both pulp and atmosphere,- and after breaking connection with the pulp supply, as by lowering the reservoir on its pivots 19, out of the range of the pipe connections 12, 15, the mold is subjected to the full suction effect as by opening up a main control valve 20. This carries ofi' free liquid in the mold and compacts the deposit, leaving the molded article in such state that it may be removed from the mold for further treatn'ient or be left in place therein for subsequent treatment.

The suction chamber may be made in the form of a bell detachably engaged with the supporting base 21'to enablethe ready removal of the mold. Before opening the chamber, it is usually freed of any liquidthat may have gathered therein by opening up the valve 23 in the drain pipe 22.

' It Will'be evident that the reinforcing effects maybe varied, for instance, by opening up the supplementary pulp supply at different periods in the filling of the mold chamber. Thus by opening up this supplementary supply before the mold is filled, the reinforcing deposit may be applied or begun before the main deposit is made.

I claim:

1. The process of molding, which commaterial and the interior of the mold through a supplementary conduit and then opening the interior of the mold to atmosphere through said same supplementary conduit.

2. The process of molding, Which comprises applying suction to the exterior of a porous mold whose interior is in communication .with a body of pulp-like material, establishing a supplementary connection between the interior of the mold and a supply of material and then opening the interior of the mold to atmosphere through said supplementary connection.

3. In combination, a pulp supply tank, a

suction chamber, a porous mold in said suction chamber having an inlet in said tank, and a conduit opening into the mold chamher and having an inlet in the tank.

' 4. In combination, a pulp supply tank, a suction chamber, a porous mold in said suction chamber having an inlet in said tank, a conduit opening into the mold chamber having an inlet in the tank and opening to atmosphere, and means controlling said inlet and opening to atmosphere.

In testimony whereof I aflix my signature.

SIMON COOPER. 

